Fusing the upper pictures requires 3.5 prism diopters of fusional convergence. Changing fixation from upper to lower pictures requires an additional 15 prism diopters Positive Fusinal Convergence, a total of 18.5 prism diopters. Keystone View Company, undated.
Item — Box: 6, File: 99, Item: 26
Scope and Contents
From the Series:
Many of the cards in this series are meant to be educational in nature. There are also some sets that are used for professional reasons. For example, the optometric community used stereographs to gauge vision and diagnose their patients.
Dates
- Copyright: undated.
Creator
- From the Collection: Broadbooks, John A. (Person)
Extent
From the Collection: 18.75 linear feet
Language of Materials
From the Collection: English
From the Collection: French
From the Collection: German
From the Collection: Spanish; Castilian
Repository Details
Part of the Truman State University, Pickler Memorial Library, Special Collections Manuscripts Repository